Extend testing

smartsim/entity/dbobject.py

@@ -132,21 +132,24 @@ def _enumerate_devices(self) -> t.List[str]:
     def _check_devices(
         device: t.Literal["CPU", "GPU"], devices_per_node: int, first_device: int,
     ) -> None:
+        if device == "CPU" and devices_per_node > 1:
+            raise SSUnsupportedError(
+                "Cannot set devices_per_node>1 if CPU is specified under devices"
+            )
+
+        if device == "CPU" and first_device > 0:
+            raise SSUnsupportedError(
+                "Cannot set first_device>0 if CPU is specified under devices"
+            )
+
         if devices_per_node == 1:
             return
 
-        if first_device < 0:
-            raise ValueError("Cannot set first_device to a negative number")
-
         if ":" in device:
             msg = "Cannot set devices_per_node>1 if a device numeral is specified, "
             msg += f"the device was set to {device} and \
                 devices_per_node=={devices_per_node}"
             raise ValueError(msg)
-        if device == "CPU":
-            raise SSUnsupportedError(
-                "Cannot set devices_per_node>1 if CPU is specified under devices"
-            )
 
 
 class DBScript(DBObject):

tests/backends/test_dbscript.py

@@ -603,7 +603,7 @@ def test_inconsistent_params_db_script(fileutils):
 
     torch_script = fileutils.get_test_conf_path("torchscript.py")
     with pytest.raises(SSUnsupportedError) as ex:
-        db_script = DBScript(
+        _ = DBScript(
             name="test_script_db",
             script_path=torch_script,
             device="CPU",
@@ -614,3 +614,15 @@ def test_inconsistent_params_db_script(fileutils):
             ex.value.args[0]
             == "Cannot set devices_per_node>1 if CPU is specified under devices"
         )
+    with pytest.raises(SSUnsupportedError) as ex:
+        _ = DBScript(
+            name="test_script_db",
+            script_path=torch_script,
+            device="CPU",
+            devices_per_node=1,
+            first_device=5,
+        )
+    assert (
+            ex.value.args[0]
+            == "Cannot set first_device>0 if CPU is specified under devices"
+        )